Drop hammer



M. c. TALCOTT April 2, 1929.

DROP HAMMER Filed Aug. :50, '1925 2 Sheets-Sheet v 1 I w @H WQ April 2, 1929. M; Q TALCQTT 1,707,499

DROP HAMMER Filed Aug. 30, 192:5 2 Sheets-Sheet '2 gwuentoz Patented Apr. 2, 1929.

ran-ire s'EATEFS smear QFFICE.

MORTON C. TALCOTT, OF EAST HARTFORD, CONNECTICUT, ASSIGNOB TO THE BILLINGS SPENCER COMPANY, OF I-IARTFORD, CONNECTICUT, A CORPORATION OF CON'' NECTICUT.

DROP HAMMER.

Application filed. August so, 1923. Serial no. 660,137.,

This invention relates to drop hammers of the sort having a hammer adapted for vertical reciprocating movement, a board connected to the hammer, a plurality of liftingrolls spaced longitudinally of the board and arranged to grip the same, and means for moving the rolls into gripping engagement with the board to raise. the same and the hammer. A drop hammer of this type is disclosed and claimed in the co-pending applicationof Raymond S. Clark, George C. Prime and Morton G. Talcott, Serial No. 523,606, filed December 20, 1921, now Patent No. 1,670,493, patented May 22, 1928.

The aim of the present invention is to pro- Vide in a drop hammer of this type various features of advantage and, more particularly, to provide a very simple, strong, and mechanically effective connection between the friction bar or actuating means and the rolls so that they are operated in such manner as to properly grip the board.

Other objects of the invention will be in part obvious, and in part pointed out herer inafter.

Figure 1 is a side. elevation, with-parts in section of so much of a drop'hammer as is necessary to illustrate my invention and Fig. 2 is a front view,,with parts in section, of the roll operatingmechanism.

Referring to the drawingsin detail, 10 is a board adapted to. be attached to a hammer (not shown) and adapted to be raised by a plurality of :rolls spaced along the board and mount-ed in ahead 11 supported on the uprights 12 between which the hammer reciprocates. There is shown, in the accompanying drawings, twosets or pairs of rolls, the rollshof one set being indicated by the numeral 13 and those of the other set by the numeral 14. The rolls of eachset are continuously rotated in opposite directions in any suitable manner, in the present instance only the driving pulleys 15 being illustrated, as the specific manner in which the rolls are driven forms no. part of the present invention.

The rolls are mounted for movement or adjustment towards and away from the board. In the present illustrative disclosure, each of the rolls is keyedto a respec tive shaft 17, and the opposite ends of these shafts are journalled in eccentrics 18 mounted for rotation in bearings 19 provided inthe sides of the head 11. The eccentrics for eachshaft are connected by yokes 20. If desired, the construction may be such that both rolls of eachyset move in unison towards and away from eachothei' to grip and release the board. Inthe presentfinstance, however, the front-rolls only are adapted to be'moved into and out of engagement with the board. The eccentric yokes 20 for the back rolls are arranged to move therolls toward and from the board for adjustment only, so as to regulate the position of these rolls relative to the board. To this end, the backer rear yokes may be connected by a link 43, and, .COQIIQOtGd to one of the yokes, may be a rod 44, the lower end of which is adjustably connectedito .the frame upright 12, as indicated by the muneral 45. i i I v I .The forward yokes are connected together by a link mechanism which, in turn, is connected to a source of board-gripping pressure constituted 'in the. present case a friction bar,an d this link mechanism is such thatthe front rolls are moved substantially in unison into and out. of, engagement with the board, and these rolls may independently accommodate themselves to the board during the lifting operation.v In the. present il lustrative disclosure, this link'mechanism includes one or more links 22 (in the present instance twosuch links beingshown) and toggle links 23 and 24. The upper. ends of the links 22 are pivotally connected to the upper yoke by means of a ,pivot member or pin 25 carried by lugs 26 extending from the forward face of the upper yoke. The op; posite or lower endsof the links 22 are connected to the lower yoke by means ,ofoblong slots anda pin 27 carriedl bysuitable lugs 28 on this yoke providing acertainlimited amount of, lost motion later referred to. The toggle link 24, at its. lower end, is join nalled on the pin 27,. and the adjacent ends of the tpggle links are connectedtogether by a pivotpin or. bolt 29. In thepresent instance, the friction bar, designated by the numeral 30, is directly connected to the pivot-al connection between the toggle, links; for instance, the upper endof the'friction bar may have a yoke 31 straddling the adjacent ends of the toggle links 23. and 24 and, pivotally connected thereto .by. the pivotmember 29. i I

The operation of the machine is briefly as follows. When the hammer approaches the end of its upward stroke, it raises the friction bar 30, thus cai'ising the same, through the links 22 and the toggle links 23 and 24, to swing the front eccentric yokes in a clockwise direction, resulting in the front rolls 'by bringing the front rolls into engagement with the board, resulting in the board and hammer being lifted. The pressure, due to the weight of the falling friction bar, is transmit-ted positively to each yoke or roll support 18, so that both rolls are positively dvanced to and against the board as distinguished from the yielding or nen-positive action of one of the rolls in the prior appli cation above referred to, and at the same time, the two rolls are capable of free, selfadjustment or compensating movement with respect to each other and the fiction bar, which is to say, that the pressure of the friction bar is equally divided as between the two rolls and both of them thus obtain an equal friction grip on the board on all occasions. This division and equalization of the pressure enables the degree of pressure of the rolls on the board to be set in the first instance so that both obtain an adequate frietion with little or no slippage and with minimum danger or over-compression of the board which, as well-known, greatly shortens its useful life.

The weight of the friction bar is exerted as compressive and tensile forces respectively on the lower and upper toggle links and for all. angular variation of said linls occurring in normal practice, the resulting divsion of the force applied is exactly equal. Such angular change of the linkage is so slight that the horizontal component of the resulting movement of the pivot pin 29 is practically negligible; its actual motion mainly vertical and no special provision or joint is therefore necessary between such pin and the friction bar, although such a joint may be provided if desired. It will, of course, be understood that the centers of the pivot pins 25 and 27 are equi-distant from the centers of the ournals of their respective roll supports or eccentrics 18 and that the eccentricities of said supports are exactly equal and in the same direction; if otherwise, the linkage angle would be required to be modified accordingly and as will be apparent, in order to keep the division equal.

Qn the upstroke of the friction bar, the pressure of both rolls on the board is insiantly relieved and, in order that both rolls shall then be positively withdrawn from the board, the throw-off links 22 are provided. The oblong slots in the lower ends of these links are made long enough so that the links do not affect or interfere with the equal division of the applied force but are nevertheless available for compelling conjoint movement of both roll supports as soon as the slight amount of lost motion represented by the slots has been taken up. This a feature of, the present invention which can be applied with greatadvantage to any system of pressureequalizin51 mechaism in which the pressure is imparted positively non-yieldingly to both or all the movable roll supports; its advantage is that it effectually avoids the polishing of the board by the roll or rolls and the consequent impairment of the friction surface which would otherwise occur when the board is in its lowest position. The spot where such polishing might occur on such occasions is the spot where it is most important that the friction co-efiicient be as high as possible, because this is the place where the roll performs its maximum work, the work of starting the hammer upwards from rest. It will be apparent to those skilled in this art, and as above stated, that this advantage applies to any equalizing positiveaction pressure system of roll control and that the necessary modification in form of the throw-off mechanism for accommodating different types of such systems can be readily made.

The connection together of the roll supports or yokes of the two back rolls, as above described, also constitutes part of this inven tion inasmuch as it is by virtue of the selfaccommodation of the front roll supports under the positive action pressure system above described, that it becomes practical to impart equal adjustment to both back rolls and accordingly there is no intended limitation in this invention to the use of said joint back roll adjustu'ient with any particular type of pressure distributing system. It will be understood that the back roll adjustment is for taking up wear.

It should be explained finally that while a gravity friction bar, as herein shown, is a simple and commonly used source of boai.'dp ri1 )ping pressure, and is preferred in the present case, the principles above described. and hereinafter identified by the claims are not dependent on the use of such a bar. When such a bar is employed, its own weig'l'it plus the weight of its attached parts and linkage is made heavy enough to overcome the friction acting on both roll supports and for this purpose may be no heavier than needed for moving a single roll if the radii of the centers of the pivot pins 25 and 27 are of appropriate length.

Thus, by the above construction, are acmom-4,99

coi-nplished, among-others, the objects: hereinbefore referredto.

As many changes, couldbe made-in the above constructionand many. apparently widely different embodiments of; this invention could be made without departing from the scopethereof, itlisintended that all matter contained in the above description or.

shown in the accompanying drawing shall be interpreted as illustrative and not in a limiting sense.

I I claim as my invention:

1. In a board drop hammer, upper and lower lifting rolls, a gravity friction bar, and a positive-action pressure-equalizing connection between said bar and said rolls.

2. In a board drop hammer upper and lower lifting rolls, a source of board-gripping pressure therefor, positive-action pressure-equalizing connection between said source and rolls and means for compelling positive withdrawal of both rolls from the board.

3. In a board drop hammer the combination of upper and lower pairs of lifting rolls, a source of board-gripping pressure therefor, a positive-action equalizing connection between said source and one roll of each pair and a single means for adjusting the working positions of both the other rolls of said pairs.

4. In a board drop hammer, the combination of a plurality of lifting rolls spaced longitudinally of the board, individual roll supports therefor, a source of board-gripping pressure and a positive-action pressureequaling connection between said source and said roll supports.

5. In a board drop hammer, the'combination of a plurality of lifting rolls. spaced. longitudinally of the board, independent roll supports therefor, a source of boardgripping pressure, and a positive-action pressare-equalizing connection between said source and roll supports, said connection including angularly related links respectively pivoted to said supports and to a common actuating member.

6. In a board drop hammer,the combination of lifting rolls spaced longitudinally of the board, a pressure source, and a positive-action pressure-equalizing connection between the same and said supports, said connection including angularly related links, the pivotal axes whereof are parallel with the roll axes.

7 In a board drop hammer, the combination of lifting rolls spaced longitudinally of the board, independent roll supports therefor, a friction bar, and a positive-action pressure-equalizing connection between said bar and both said roll supports.

8. In a board drop hammer, the combination of lifting rolls spaced longitudinally of the board and journalled in independent roll; supports, a zssource of; board-gripping pressure, a positive-action pressure-equalizing connect1on between said source .and said supports. and a positive throw-off means included in, .OFrflSSOClZtllGd. with, said connection. Y

9. In a board dropchammer the. combination of lifting rolls spaced longitudinally of from the board.

10. In a drop hammer, a frame, a hammer suitably guided therein, a board connected to the hammer, a plurality of lifting rolls spaced apart longitudinally of the board,

eccentrics for moving said rolls relative to said board, yokes connecting the eccentrics for each roll, an actuating member connected to the respective yokes, and a link connecting said yokes, said link having a slot and pin connection with one of said yokes whereby the yokes have a slight relative motion.

11. In a drop hammer, a frame, a hammer suitably guided therein, a board connected to said hammer, a plurality of lifting rolls spaced apart longitudinally of the board, eccentrics for moving the rolls relative to the board, a yoke connecting the eccentrics for each roll, an actuating member, a link between said member and each of said yokes, and a connecting link between said yokes and permitting a slight relative motion therebetween.-

12. In a drop hammer, a frame, a hammer suitably guided therein, a board connected to said hammer, a plurality of lifting rolls spaced apart longitudinally of said board, eccentrics to move said rolls into engagement with the board, yokes connecting the eccentrics of each roll, a pair of toggle links pivotally connected at their free ends to the respective yokes, a friction bar directly PlV- oted to both said toggle links at their adja-' cent ends and a link between saidyokes and having a slight lost motion relative to one of them.

13. In a board drop hammer the combination of upper and lower pairs of lifting rolls journalled in independent roll supports, a source of board-gripping pressure, a pressure-equalizing connection between said source and the roll support of one roll of each pair and a single means for simultaneously adjusting the working position of the other rolls of said pairs.

14L. In a board drop hammer, upper and lower pairs of lifting rolls, a source of boardgripping pressure, a pressure-equalizing connection between said source and one roll of each pair, an eccentric support for the other rolls of each pair and means for simultaneously angularly adjusting said eccentrics. 15. In a board drop hammer, pairs of lifting rolls spaced longitudinally of the 5 board, a source of board-gripping pressure therefor, a positive-action pressure-equalizing connection between said source and one roll of each pair, said connection being provided With means for compelling positive conjoint Withdrawal of said rolls, and means for simultaneously changing the Working positions of the other rolls 0i said pairs.

MORTON G. TALOOTT. 

